Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 2: Correlated Electrons: Electronic Structure Calculations and Other Theoretical Topics
TT 2.2: Vortrag
Montag, 1. April 2019, 09:45–10:00, H7
Modeling the X-ray absorption spectra and magnetism in UGa2 using LDA+U and LDA+DMFT — •Banhi Chatterjee and Jindrich Kolorenc — Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
We study the electronic structure and magnetic properties of the uranium inter-metallic compound UGa2. We focus on theoretical modeling of the M-edge X-ray absorption spectra (XAS), and investigate the magnetic moments formed at the uranium atoms. Correlations between the uranium 5f electrons are considered using the static orbital-dependent LDA+U functional and the dynamical mean-field theory (LDA+DMFT). We show that the LDA+DMFT reproduces the XAS spectra more accurately than LDA or LDA+U. Distinctive spectral features are identified with atomic multiplets, which favors the localized picture of the 5f electrons in this compound. It turns out that LDA substantially underestimates the size of the magnetic moments at the uranium atoms and even LDA+U does not reach the experimental moments with reasonable values of Coulomb U. We investigate whether LDA+DMFT improves the description of the magnetic moments.